Load accelerating and decelerating pulley means

ABSTRACT

A lifting system, as for an elevator, provides speed control that is substantially mechanical rather than electrical in nature, with advancement in reliability. It comprises, in combination, A. A ROTARY DRIVE HAVING SUBSTANTIALLY CONSTANT OUTPUT SPEED, B. A PULLEY OPERATIVELY CONNECTED TO THE DRIVE TO BE ROTATED, THE PULLEY HAVING AN AXIS OF ROTATION, C. LOAD IMPOSING STRUCTURE TO BE DISPLACED BETWEEN SPACED REST POSITIONS, AND D. A FIRST LOAD TRANSMITTING LINE OPERATIVELY CONNECTED TO SAID STRUCTURE AND ALSO WOUND ABOUT THE PULLEY TO AN EXTENT CORRESPONDING TO TURNING THEREOF BY THE DRIVE, THERE BEING LOCI OF LINE DEPARTURE POINTS FROM THE PULLEY AND WHICH HAVE RADII FROM THE PULLEY AXIS THAT PROGRESSIVELY INCREASE AS THE PULLEY ROTATES IN CORRESPONDENCE TO INCREASED DISPLACEMENT OF THE STRUCTURE FROM A REST POSITION.

United States Patent [191 Gindroz, Jr.

[4 1 Dec. 10, 1974 LOAD ACCELERATING AND DECELERATING PULLEY MEANS [75] Inventor: Francis H. Gindroz, Jr., Torrance,

Calif.

[73] Assignee: Task Corporation, Anaheim, Calif.

[22] Filed: Mar. 16, 1972 [2]] Appl. No.: 235,448

Related US. Application Data [63] Continuation of Ser. No. 21,660, March 23, 1970.

Primary Examiner'Richard A. Schacher Assistant Examiner-James L. Rowland Attorney, Agent, or FirmWilliam W. Haefliger [5 7 ABSTRACT A lifting system, as for an elevator, provides speed control that is substantially mechanical rather than electrical in nature, with advancement in reliability. it

comprises, in combination,

a. a rotary drive having substantially constant output speed,

b. a pulley operatively connected to the drive to be rotated, the pulley having an axis of rotation,

c. load imposing structure to be displaced between spaced rest positions, and

d. a first load transmitting line operatively connected to said structure and also wound about the pulley to an extent corresponding to turning thereof by the drive, there being loci of line departure points from the pulley and which have radii from the pulley axis that progressively increase as the pulley rotates in correspondence to increased displacement of the structure from a rest position.

9 Claims, 5 Drawing Figures PATENTEL, SEC! 0 I974 SHEET 2 OF 3 f/vvs/vroz R/WC/S H. Gwaeoz ck LOAD ACCELERATING AND DECELERATING PULLEY MEANS This is a Continuation, of application Ser. No. 2l,660, filed Mar. 23, 1970.

BACKGROUND OF THE INVENTION This invention relates generally to elevator drives, and more particularly concerns simplification in elevator drive speed control through replacement of electrical components with mechancial system components.

Elevator acceleration and deceleration requirements have in the past led those skilled in the art to the use of elaborate and expensive speed control systems. The latter involve such electrical components as two-speed electrical motors, extra control relays and switches, all of which increase the possibility of malfunction of the elevator system. This problem becomes acute where the elevator is to be used on large passenger aircraft as for elevating food and other passenger supplies between decks.

SUMMARY OF THE INVENTION It is a major object of the invention to provide a solution to the above problem characterized in that the resultant elevator speed control system is substantially mechanical rather than electrical in nature, with resultant advancement in reliability. The System is also simple in design and operation, less expensive to construct, and provides certain safety features.

Basically, the lifting system comprises, in combination, a rotary drive having substantially constant output speed; a pulley operatively connected to the drive so as to be rotated about the pulley axis; load imposing structure to be displaced between spaced rest positions; and a first load transmitting line (as for example a cable) operatively connected to the load imposing structure and also wound about the pulley to an extent corresponding to pulley turning by the drive, there being loci of line departure points from the pulley which have radii from the pulley axis that progressively increase as the pulley rotates in correspondence to increased displacement of the structure from rest position at a first station, thereby to accelerate the structure. As will be seen, a second load transmitting line is typically operatively connected to the structure and pulley to unwind from the latter as the first line is wound on the pulley, there being loci of second line departure points from the pulley which have radii from the pulley axis that progressively increase as the pulley rotates in correspondence to increased displacement of the structure from rest position, the first and second lines extending generally oppositely from the structure and being in tension so that the lines resist uneven acceleration of said structure. In this regard, the windings of the two lines on the pulley may be interleaved. and the pulley may be grooved to define the described loci and a double lead for the two lines.

Additional objects of the invention include the provision of first and second line departure points from the pulley which have radii from the pulley axis that progressively decrease as the pulley rotates in correspondence to structure approach to rest position at a second station; the provision of a redundant or second pulley connected to the drive and another or redundant load transmitting line connected between that pulley and the load imposing structure, with loci of line departure from the second pulley that also increase as the second pulley rotates to increase the structure displacement from rest position; the provision of load imposing structure in the form of a mass (such as an elevator cage), and a load equalizer element pivotally connected to the mass, the first and third lines connected to the element at spaced locations relative to the pivot such that the load transmitted by those lines is approximately equalized; the provision of a drive that includes a constant speed electrical motor; and the provision for down-haul of the elevator, with auxiliary manual operation.

These and other objects and advantages of the invention, as well as details of an illustrative embodiment, will be more fully understood from the following specification and drawings, in which:

DRAWING DESCRIPTION FIG. 1 is a front elevation taken on lines 1-1 of FIG. 2 and showing one application of the invention;

FIG. 2 is a side elevation;

FIG. 3 is an enlarged elevation showing the equalizer bar;

FIG. 4 is a plan view taken on line 4-4 of FIG. 3; and

FIG. 5 is a plan view of a rotary drive and pulley system embodying the invention.

DESCRIPTION OF PREFERRED EMBODIMENT In the drawings, a rotary drive is indicated at 10, and may include a pair of identical motors I1 and 12 coupled together at 13 by appropriate gearing. The motors may with advantage comprise single speed induction motors, and suitable speed reduction gearings l4 and 15 couples the motor output to the approximately constant speed drive shafts l6 and 17 to which pulleys l8 and 19 are respectively connected. The pulleys have axes of rotation indicated at 20 and 21.

It will be understood that load imposing structure is to be displaced between spaced rest positions by the drive. That structure may with advantage comprise an elevator cage 22 movable between raised and lowered rest positions as seen in FIG. 2, which also shows a second cage 23 driven by a similar drive 24. Frame structure to mount the drives and form the elevator shaft includes vertical members 25 and horizontal members 26 and 27, appropriate cage guides being usable, if needed. If used on an aircraft as a food elevator, the cabin ceiling may be located as at 28, and upright panels 29-32 may enclose the elevator shaft.

In accordance with the invention, a first load transmitting line, as for example cable 33, is operatively connected to the load imposing structure, i.e. the elevator cage, and is also wound about the pulley 18 to an extent corresponding to turning of the pulley by the drive. Also, the winding of the line on the pulley is characterized by line departure points from the pulley with radii from the pulley axis that progressively increase as the pulley rotates in correspondence to increased displacement of the elevator structure from a rest position, say lower rest position. For example, note that the radius progressively increases from dimension 34a to dimensions 34b and 34c in FIG. 5, thereby to provide smooth acceleration of the elevator cage as it is lifted up from lowermost position, despite the fact that the rotary drive has approximately constant output speed.

A second line, as for example hold-down cable 35, operatively connects the load imposing structure and pulley to unwind or pay-off from the pulley as the first line winds onto the pulley. Again, the pulley is formed so that there are loci of second line departure points from the pulley which have radii that progressively increase as the pulley rotates in correspondence to increased displacement of the elevator structure from rest position, say lower rest position. For example, note that the radius progressively increases from dimension 37a to dimensions 37b and 37c. Also note that the windings of the first and second lines 33 and 35 on the pulley 18 are interleaved as by provision of double lead grooving on the pulley to receive the cables, spiral groove 38 receiving the cable 33 and matching spiral groove 36 receiving the cable 35.

Whereas line or cable 33 extends upwardly from the cage to the pulley, line 35 extends downwardly-from the cage to an idler sheave 39 and then returns upwardly to the drive pulley 18, as is clear from FIG. 1. Line 35 is taut and functions to hold the cage down against upward gust loads, as during sharp upward or downward motion of the aircraft. Note that when the cage is at upper rest position, as for example the passenger deck station, the lifting cable 33 is stored on the pulley and the down-haul or hold-down cable 35 is almost completely unwound (and vice versa when the cage is at lowermost rest position).

It will further be noted that the pulley 18 is grooved to define other loci of first line 33 departure points which have radii from axis that progressively decrease as the pulley rotates in correspondence to elevator structure approach to rest position at a second station (for example upper position), the same being true for the second line 35 that interleaves with the first line on the pulley. See in this regard radii 41a and 41b associated with line 33, and radii 46a and 46h associated with line 35. Accordingly, as the elevator approaches the second station rest position, it smoothly decelerates, the motor output speed remaining approximately constant.

Also contemplated is the provision ofa second pulley (as for example pulley l9) operatively connected to the drive to be rotated, there being a third load transmitting line (as for example cable 42) connected to the elevator structure and wound about the second pulley to an extent corresponding to turning thereof by the drive. Pulley 19 is spirally grooved as at 43 to receive the cable line 42, there being loci of third line departure points from the second pulley and which have radii from the pulley axis that increase progressively as the pulley rotates in correspondence to increased displacement ofthe elevator from rest position (say lower position). See for example the radii 47a and 47b. Also, the groove 43 progressively diminishes in radius as the elevator approaches upper rest position. See radii 48a and 481). Line 42 provides a redundant support for the elevator cage for safety in case of malfunction of line 33. Also, it bears at least part of the elevator imposed load.

The load imposing structure may typically include, in addition to the mass or weight of the elevator structure, a load sharing element pivotally connected to the elevator, the first and third lines 33 and 42 being connected to that element at spaced locations relative to the pivot connection such that the load transmitted by the lines is shared. In the example seen in FIG. 3, a

mounting bracket 48 is attached at 49 to the cage; a transverse down-haul bar 50 centrally pivotally connected at 51 to the bracket 48, and a lift load equalizer bar or element 52 is also pivotally connected at 51 to the bracket. Cables 33 and 42 may be attached to bar 52 at locations equidistant from and at opposite sides of a vertical plane 53 through pivot 51, as shown, for load equalization. A lost motion pin and slot connection between the bars 50 and 52 allows the bar 52 to tilt relative to bar 50 and equalize the cable load. Note the pin 54 attached to bar 50 and the accurate slot 55 in the bar 52 and receiving the pin, the slot having ends 55a and 55b to limit tilting of bar 52 relative to bar 50.

The cable or line 35 may be centrally connected to the downhaul bar 50 as at 56. Means (as at 57) in series with that cable yieldably cushions the connection of the cable 35 to the elevator in the event of sudden upward displacement of the elevator. To this end, a compression spring 57a in-housing 58 transmits loading between that housing (attached to cable 35) and a plunger plate 59 attached to the bar 50.

Finally, the cage may be manually lowered in an emergency as by pulling on auxiliary cables 60 and 61 attached to down-haul bar 50 as shown. Such pull may be exerted via manually operable cable drives located on the elevator at 62, or located on the cage support structure at 63 and 64.

I claim:

1. In a lifting system, the combination comprising a. a rotary drive having substantially constant output speed,

b. a pulley operatively connected to the drive to be rotated, the pulley having an axis of rotation,

c. load imposing structure to be displaced between spaced rest positions,

(1. a first load transmitting line operatively connected to said structure and also wound about the pulley to an extent corresponding to turning thereof by the drive, there being certain loci of line departure points from the pulley and which have radii from the pulley axis that progressively increase as the pulley rotates in correspondence to increased displacement of the structure from a rest position at a first station, and there being other loci of line departure points from the pulley which have radii from the pulley axis that progressively decrease as the pulley rotates in correspondence to structure approach to rest position at a second station, the pulley having its largest diameter line engaging portion between said certain and other loci of line departure points,

e. there being a second load transmitting line operatively connected to said structure and pulley to unwind from the pulley as the first line winds on the pulley, there being certain loci of second line departure points from the pulley, and which have radii from the pulley axis that progressively increase as the pulley rotates in' correspondence to increased displacement of the structure from rest position at the first station, and other loci of second line departure points from the pulley which have radii from the pulley axis that progressively decrease as the pulley rotates in correspondence to structure approach to rest position at the second station, the first and second lines extending generally oppositely from the structure and being in tension so that the lines resist uneven acceleration of the structure, and each of the first and second lines wrapping about the pulley over substantially the same axial length thereof including said largest diameter portion, said lines wrapping in interleaved relation in different grooves defined by the pulley.

2. The combination of claim 2 wherein the pulley is grooved to define said'loci associated with said line departure points, the grooves defining a double lead.

3. The combination of claim 1 wherein the drive comprises a constant speed electrical motor.

4. In a lifting system, the combination comprising a. a rotary drive having substantially constant output speed,

b. a first pulley operatively connected to the drive to be rotated, the pulley having an axis of rotation,

c. load imposing structure to be displaced between spaced rest positions,

d. a first load transmitting line operatively connected to said structure and also wound about the pulley to an extent corresponding to turning thereof by the drive, there being certain loci of line departure points from the pulley and which have radii from the pulley axis that progressively increase as the pulley rotates in correspondence to increased displacement of the structure from a rest position at a first station, and there being other loci of line departure points from the pulley which have radii from the pulley axis that progressively decrease as the pulley rotates in correspondence to structure approach to rest position at a second station, the pulley having its largest diameter line engaging portion between said certain and other loci of line departure points, and

e. a second pulley operatively connected to the drive i to be rotated and having an axis of rotation, there being a third load transmitting line connected to said structure and wound about the second pulley to an extent corresponding to turning thereof by the drive, there being loci of third line departure points from the second pulley and which have radii from the pulley axis that increase progressively as the pulley rotates in correspondence to increased displacement of the structure from said first rest position, and thereafter decrease progressively as the second pulley rotates in correspondence to structure approach to rest position at the second station.

5. The combination of claim 4 wherein said load imposing structure includes a mass and a load sharing element pivotally connected to said mass, the first and third lines being connected to said element at spaced locations relative to the pivotal connection such that the load transmitted thereby is shared.

6. The combination of claim 5 wherein said mass comprises an elevator cage in an aircraft, said first and third lines extending upwardly from said equalizer element, and said second line extending downwardly relative to said element.

7. The combination of claim 6 including a downhaul part pivotally connected to said mass, said second line operatively connected to said part.

8. The combination of claim 7 including means yieldably cushioning the connection of said second line to said part.

9. The combination of claim 7 including auxiliary cable and drive means manually operable in an emergency to lower the cage. 

1. In a lifting system, the combination comprising a. a rotary drive having substantially constant output speed, b. a pulley operatively connected to the drive to be rotated, the pulley having an axis of rotation, c. load imposing structure to be displaced between spaced rest positions, d. a first load transmitting line operatively connected to said structure and also wound about the pulley to an extent corresponding to turning thereof by the drive, there being certain loci of line departure points from the pulley and which have radii from the pulley axis that progressively increase as the pulley rotates in correspondence to increased displacement of the structure from a rest position at a first station, and there being other loci of line departure points from the pulley which have radii from the pulley axis that progressively decrease as the pulley rotates in correspondence to structure approach to rest position at a second station, the pulley having its largest diameter line engaging portion between said certain and other loci of line departure points, e. there being a second load transmitting line operatively connected to said structure and pulley to unwind from the pulley as the first line winds on the pulley, there being certain loci of second line departure points from the pulley, and which have radii from the pulley axis that progressively increase as the pulley rotates in correspondence to increased displacement of the structure from rest position at the first station, and other loci of second line departure points from the pulley which have radii from the pulley axis that progressively decrease as the pulley rotates in correspondence to structure approach to rest position at the second station, the first and second lines extending generally oppositely from the structure and being in tension so that the lines resist uneven acceleration of the structure, and each of the first and second lines wrapping about the pulley over substantially the same axial length thereof including said largest diameter portion, said lines wrapping in interleaved relation in different grooves defined by the pulley.
 2. The combination of claim 2 wherein the pulley is grooved to define said loci associated with said line departure points, the grooves defining a double lead.
 3. The combination of claim 1 wherein the drive comprises a constant speed electrical motor.
 4. In a lifting system, the combination comprising a. a rotary drive having substantially constant output speed, b. a first pulley operatively connected to the drive to be rotated, the pulley having an axis of rotation, c. load imposing structure to be displaced between spaced rest positions, d. a first load transmitting line operatively connected to said structure and also wound about the pulley to an extent corresponding to turning thereof by the drive, there being certain loci of line departure points from the pulley and which have radii from the pulley axis that progressively increase as the pulley rotates in correspondence to increased displacement of the structure from a rest position at a first station, and there being other loci of line departure points from the pulley which have radii from the pulley axis that progressively decrease as the pulley rotates in correspondence to structure approach to rest position at a second station, the pulley having its largest diameter line engaging portion between said certain and other loci of line departure points, and e. a second pulley operatively connected to the drive to be rotated and having an axis of rotation, there being a third load transmitting line connected to said structure and wound about the second pulley to an extent corresponding to turning thereof by the drive, there being loci of third line departure points from the second pulley and which have radii from the pulley axis that increase progressively as the pulley rotates in correspondence to increased displacement of the structure from said first rest position, and thereafter decrease progressively as the second pulley rotates in correspondence to structure approach to rest position at the second station.
 5. The combination of claim 4 wherein said load imposing structure includes a mass and a load sharing element pivotally connected to said mass, the first and third lines being connected to said element at spaced locations relative to the pivotal connection such that the load transmitted thereby is shared.
 6. The combination of claim 5 wherein said mass comprises an elevator cage in an aircraft, said first and third lines extending upwardly from said equalizer element, and said second line extending downwardly relative to said element.
 7. The combination of claim 6 including a downhaul part pivotally connected to said mass, said second line operatively connected to said part.
 8. The combination of claim 7 including means yieldably cushioning the connection of said second line to said part.
 9. The combination of claim 7 including auxiliary cable and drive means manually operable in an emergency to lower the cage. 